Imaging apparatus

Abstract

An imaging apparatus includes a photometry unit dividing a subject into a plurality of regions and performing a photometry, a first calculating unit calculating a first control value based on a photometry result of the photometry unit, a comparing unit comparing the first control value with a maximum value of photometry values in the plurality of regions, a second calculating unit correcting the first control value depending on a comparison result by the comparing unit to calculate a second control value, an image pickup unit picking up an image of the subject according to the second control value and generates an image data, and a third calculating unit calculating a lightness improvement amount for a correction of dark area gradation of the image data depending on the comparison result. Therefore, optimum exposure adjustment and correction of dark area gradation can be performed depending on the subject.

1. An imaging apparatus comprising:
 a photometry unit dividing a subject into a plurality of regions and performing a photometry; 
 a first calculating unit calculating a first exposure control value based on a photometry result of the photometry unit; 
 a comparing unit comparing the first exposure control value with a maximum value of photometry values in the plurality of regions; 
 an estimating unit estimating a saturation amount of a highlight part of an image depending on a comparison result by the comparing unit; 
 a second calculating unit correcting the first exposure control value using the saturation amount being estimated by the estimating unit to calculate a second exposure control value in which an exposure control result of when using the second exposure control value is under than that of when using the first exposure control value; 
 an image pickup unit picking up an image of the subject according to the second exposure control value and generating an image data; 
 a third calculating unit calculating a lightness improvement amount for a correction of dark area gradation of the image data depending on the comparison result by the comparing unit; 
 a low-pass filter processing unit performing processing by a low-pass filter on the image data generated in the image pickup unit to generate a low-pass image; 
 a correcting unit performing a correction to improve a lightness of dark area gradation of the image data generated in the image pickup unit according to the lightness improvement amount calculated by the third calculating unit and the low-pass image; and 
 a recording unit recording the image data after correction by the correcting unit. 
 
     
     
       2. The imaging apparatus according to  claim 1 , wherein
 the third calculating unit provides an upper limit to the lightness improvement amount depending on an imaging sensitivity of the image pickup unit. 
 
     
     
       3. The imaging apparatus according to  claim 1 , further comprising:
 a light emission unit illuminating a subject; and 
 a luminescence amount calculating unit calculating a luminescence amount for a luminescence by the light emission unit, wherein 
 the luminescence amount calculating unit corrects the luminescence amount depending on the lightness improvement amount calculated by the third calculating unit. 
 
     
     
       4. The imaging apparatus according to  claim 1 , wherein
 the third calculating unit sets the lightness improvement amount as a predefined fixed amount depending on a shooting condition at time of shooting by the image pickup unit. 
 
     
     
       5. The imaging apparatus according to  claim 4 , wherein
 the photometry unit selectively performs any of a plurality of photometry modes including at least one of a center-weighted photometry mode and a spot photometry mode, and 
 the third calculating unit sets the lightness improvement amount as the fixed amount if any of the center-weighted photometry mode and the spot photometry mode is performed at the photometry unit at time of shooting by the image pickup unit. 
 
     
     
       6. The imaging apparatus according to  claim 4 , further comprising
 a light emission unit illuminating a subject, wherein 
 the third calculating unit sets the lightness improvement amount as the fixed amount if an illumination by the light emission unit is performed at time of shooting by the image pickup unit. 
 
     
     
       7. The imaging apparatus according to  claim 6 , wherein
 the light emission unit selectively performs any of a plurality of luminescence modes including at least one of a daylight synchronous mode and a slow synchronous mode, and 
 the third calculating unit sets the lightness improvement amount as the fixed amount if a luminescence mode other than the center-weighted photometry mode and the spot photometry mode is performed at the light emission unit at time of shooting by the image pickup unit. 
 
     
     
       8. An imaging apparatus comprising:
 a photometry unit dividing a subject into a plurality of regions and performing a photometry; 
 a first calculating unit calculating a first exposure control value based on a photometry result of the photometry unit; 
 a first comparing unit comparing the first exposure control value with a maximum value of photometry values in the plurality of regions; 
 an estimating unit estimating a saturation amount of a highlight part of an image depending on a comparison result by the comparing unit; 
 a second calculating unit correcting the first exposure control value using the saturation amount being estimated by the estimating unit to calculate a second exposure control value in which an exposure control result of when using the second exposure control value is under than that of when using the first exposure control value; 
 an image pickup unit picking up an image of the subject according to the second exposure control value and generating an image data; 
 a second comparing unit comparing the second exposure control value with a minimum value of photometry values in the plurality of regions; 
 a third calculating unit calculating a lightness improvement amount for a correction of dark area gradation of the image data depending on the comparison result by the second comparing unit; 
 a low-pass filter processing unit performing processing by a low-pass filter on the image data generated in the image pickup unit to generate a low-pass image; 
 a correcting unit performing a correction to improve a lightness of dark area gradation of the image data generated in the image pickup unit according to the lightness improvement amount calculated by the third calculating unit and the low-pass image; and 
 a recording unit recording the image data after correction by the correcting unit. 
 
     
     
       9. The imaging apparatus according to  claim 8 , wherein
 the photometry value used for a comparison in the first comparing unit and the photometry value used for a comparison in the second comparing unit are photometry values acquired from different divided regions at the photometry unit. 
 
     
     
       10. An imaging apparatus comprising:
 a photometry unit dividing a subject into a plurality of regions and performing a photometry; 
 a first calculating unit calculating a first exposure control value based on a photometry result of the photometry unit; 
 a first comparing unit comparing the first exposure control value with a maximum value of photometry values in the plurality of regions; 
 a second comparing unit comparing the first exposure control value with a minimum value of photometry values in the plurality of regions; 
 an estimating unit estimating a saturation amount of a highlight part of an image depending on a comparison result by the comparing unit and a comparison result by the second comparing unit; 
 a second calculating unit correcting the first exposure control value using the saturation amount being estimated by the estimating unit to calculate a second exposure control value in which an exposure control result of when using the second exposure control value is under than that of when using the first exposure control value; 
 an image pickup unit picking up an image of the subject according to the second exposure control value and generating an image data; 
 a third calculating unit calculating a lightness improvement amount for a correction of dark area gradation of the image data depending on the comparison result by the first comparing unit and the comparison result by the second comparing unit 
 a low-pass filter processing unit performing processing by a low-pass filter on the image data generated in the image pickup unit to generate a low-pass image; 
 a correcting unit performing a correction to improve a lightness of dark area gradation of the image data generated in the image pickup unit according to the lightness improvement amount calculated by the third calculating unit and the low-pass image; and 
 a recording unit recording the image data after correction by the correcting unit.